A new multi-code high speed mobile radio transmission scheme using cyclic modified M-sequence

This paper proposes a new parallel transmission scheme using cyclic codes generated from a modified M-sequence, which is biased with constant direct current (DC) on an M-sequence and inserted the guard chips before and after this biased M-sequence. In the proposed system, the orthogonality of the codes is kept not only between parallel transmission channels but also between direct and delayed waves within guard chips. The bit error rate (BER) performance was evaluated by computer simulations. As a result, the proposed system can transmit several Mbps in the high speed double spike Rayleigh fading channel with better quality in comparison with conventional multi-code CDM transmission.